vpXfamily: grammar and format fixes

Author: OrangeChannel

src/encoding/codecs/vpXfamily.md

@@ -1,38 +1,38 @@
 # Encoding for vp9/av1
 
-the vpX/aom family of codecs (vp8,vp9 and av1) are the standard for
+The vpX/aom family of codecs (vp8, vp9, and av1) are the standard for
 royalty-free video encoding and have been for the past 10 years.
-the vpX/aom family of codecs is widely supported for playback 
+The vpX/aom family of codecs is widely supported for playback
 in all modern browsers (excluding safari, but with apple's entry
-into the alliance for open media this is expected to change)
+into the alliance for open media, this is expected to change)
 and many hardware devices such as gaming consoles and phones.
-The second generation and third generation of vpX/aom family codecs
+The second and third generation of vpX/aom family codecs
 (vp9 and av1) provide better video quality at smaller file sizes
-compared to h.264 however av1's encoders have yet to reach the
-same maturity as x264 or x265 and so a comparison cannot
-yet be drawn between av1 and it's competitor h.265 on detail
-retention. 
+than h.264. However, av1's encoders have yet to reach the
+same maturity as x264 or x265,
+so we cannot yet draw a comparison between av1 and its competitor h.265
+on detail retention.
 
 libvpx is a mature, feature-complete, free, open-source encoder
-for the vp8/vp9 video formats which provides maximum
+for the vp8/vp9 video formats, providing maximum
 compression for vp9.
 
 SVT-VP9 is a non-feature-complete, speed-optimized, free,
-open-source encoder for the vp9 video format which provides
-high-speed highly parallel encoding.
+open-source encoder for the vp9 video format, which provides
+high-speed, highly parallel encoding.
 
 libaom is a feature-complete, free, open-source encoder
-for the av1 format and future formats in the family
-such as the currently in early development av2 format.
-On average libaom provides 20% better compression than h.265
-but due to lack of maturity can struggle at times with loss
-of detail.
+for the av1 format and future formats in the family,
+such as the av2 format (currently in early development).
+On average, libaom provides 20% better compression than h.265
+but can sometimes struggle with a loss of detail
+due to lack of maturity.
 
 SVT-AV1 is a non-feature-complete, speed-optimized, free,
-open-source encoder for the av1 video format which provides
-high-speed highly parallel encoding. By aiming to provide
-lower levels of compression at a higher speed it has been able
-to reach a higher level of maturity quicker than libaom.
+open-source encoder for the av1 video format, which provides
+high-speed, highly parallel encoding.
+By aiming to provide lower levels of compression at a higher speed
+it has reached a higher level of maturity quicker than libaom.
 
 
 ## Prerequisites
@@ -42,7 +42,7 @@ To get started, you'll need a few things:
 - A video to encode—for the examples,
   use a yuv file generated by VapourSynth,
   which you should be able to do
-  if you've been following the previous sections of this guide
+  if you've been following the previous sections of this guide.
 - Either libvpx and libaom or SVT-VP9 and SVT-AV1
 
 Here's how we get a copy of these encoders:
@@ -54,7 +54,7 @@ libaom (git) may be built from source by downloading the sources using git-bash
 ```
 git clone https://aomedia.googlesource.com/aom
 mkdir build
-cd build 
+cd build
 cmake ../aom
 make
 ```
@@ -88,35 +88,35 @@ Here are a few examples:
 ## Getting Started
 
 All four encoders are highly configurable,
-and the options will overwhelm you at first.
+and the options might overwhelm you at first.
 But we will provide you with some basic
 parameters and guidance to start with for your
 first encodes. The encoders in this family have
-most of their options named similarly to each other
-so for simplicity's sake we will use libvpx and
+most of their options named similarly to each other,
+so for simplicity's sake, we will use libvpx and
 libaom for these examples.
 
 ### On the topic of patent and copyright.
 
-the vpX/aom family of codecs are royalty-free codecs,
+The vpX/aom family of codecs are royalty-free,
 meaning you do not have to pay to use technologies
 required to design, distribute or use a vpX/aom encoder
-or decoder. This differs from h.264 and h.265 which
-require payment for use of technologies required to
-design a h.264 or h.265 encoder or decoder.
+or decoder. This differs from h.264 and h.265,
+which require payment for the use of the technologies needed to
+design an h.264 or h.265 encoder or decoder.
 
-Unfortunately because of this vpX/aom family codecs
-are best used in 2-pass mode (due to some technologies
+Unfortunately, because of this, vpX/aom family codecs
+are best used in two-pass mode due to some technologies
 required to provide a satisfactory single pass encoder
-being subject to patent royalties imposed by the mpeg
-group (the creators of h.264 and h.265)). As such all
-examples in this guide are 2-pass encodes.
+being subject to patent royalties imposed by the MPEG
+alliance (the creators of h.264 and h.265). As such,
+all examples in this guide are two-pass encodes.
 
 ### Example 1: General-Purpose Encoding with VP9
 
 Open up a terminal window,
 and navigate to the folder
-where your VapourSynth script lives (for a 1080p or larger 16:9 video)
+where your VapourSynth script lives (for a 1080p or larger 16:9 video).
 Let's run the following commands:
 
 ```
@@ -132,7 +132,7 @@ Let's run through what each of these options means:
 ##### `vspipe --y4m myvideo.vpy temp.y4m`
 
 This portion loads your VapourSynth script
-and saves to temp.y4m
+and saves it to temp.y4m.
 
 ##### `--codec=vp9`
 
@@ -142,12 +142,12 @@ be encoding using the vp9 codec.
 
 ##### `--passes=2`
 
-This tells vpxenc that we're doing 2 pass encoding.
+This tells vpxenc that we're doing two-pass encoding.
 
 
 ##### `--pass=X`
 
-this tells vpxenc which pass we are performing.
+This tells vpxenc which pass we are performing.
 
 
 ##### `--fpf=passdata.bin`
@@ -157,16 +157,16 @@ This tells vpxenc where to store the statistics used for the second pass.
 
 ##### `--row-mt=1`
 
-This tells vpxenc to multithread on tile-rows, not just tile columns.
+This tells vpxenc to multithread on tile rows, not just tile columns.
 This is an important parameter because it greatly reduces encode time.
 
 
 ##### `--cpu-used=X`
 
 This is like x264's presets.
-It allows you to switch between faster encoding,
+It allows you to switch between faster encoding
 or higher quality.
-The full list of presets, mapped to their h.264 equivalents is
+The full list of presets mapped to their h.264 equivalents is
 
 0. placebo
 1. veryslow
@@ -179,30 +179,29 @@ The full list of presets, mapped to their h.264 equivalents is
 8. superfast
 9. ultrafast
 
-Unlike h.264 0 and 9 are reasonably useful if you want to get
-maximum compression (and don't care about encoding time) or 
-maximum encoding speed (and don't care about getting good quality 
-(realtime video for example)) respectively.
+Unlike with h.264, 0 and 9 are reasonably useful if you want to get
+maximum compression (and don't care about encoding time) or
+maximum encoding speed (and don't care about getting good quality
+(real-time video, for example)), respectively.
 
 ##### `--deadline best`
 
-this instructs the encoder to be more strict about the quality of
-the encoding and not to move on until it is 100% satisfied with
-that frame.
+This instructs the encoder to be more strict about the encoding quality
+and to not move on until it is 100% satisfied with that frame.
 
 
 ##### `--auto-alt-ref=2`
 
-This is a option that determines how keyframes are chosen. If you
-are tuning for maximum playback compatability choose 1, if you are
-tuning for maximum quality choose 2.
+This is an option that determines how keyframes are chosen. If you
+are tuning for maximum playback compatibility, choose 1; if you are
+tuning for maximum quality, choose 2.
 
 
 ##### `--lag-in-frames=25`
 
 This option allows keyframes to be moved forward or back by this
-number of frames which allows for better keyframe placement.
-larger numbers like 25 are better suited for anime.
+number of frames, allowing for better keyframe placement.
+Larger numbers like 25 are better suited for anime.
 
 
 ##### `--arnr-strength=0`
@@ -213,31 +212,31 @@ video with vapoursynth.
 
 ##### `--aq-mode=2`
 
-This option tells the encoder to rely on how complex the motion
-of each frame is to determine the adaptive quantization. In
-other words, more motion in more directions equals more bits
+This option tells the encoder to rely on how complex
+each frame's motion is to determine the adaptive quantization.
+In other words, more motion in more directions equals more bits
 devoted to that frame.
 
 
 ##### `--frame-parallel=0`
 
-This option allows for parallel decoding of the video, it reduces
-quality so we disable it.
+This option allows for parallel video decoding, reducing quality,
+so we disable it.
 
 
 ##### `--tile-columns=2` and `--tile-rows=1`
 
 These options determine how the encoder breaks up the frame into
-chunks for encoding. The more chunks the more threads can be used
+chunks for encoding. The more chunks, the more threads can be used
 for encoding. One important note here is that the values of this
-parameter are in the form of $$2^{x}$$ meaning that the number of
-columns and rows with these values is actually 4 and 2 
+parameter are in the form of \\(2^{x}\\), meaning that the number of
+columns and rows with these values is actually 4 and 2,
 respectively. Tiles cannot be smaller than 65536 pixels in area.
 
 
 ##### `--threads=8`
 
-Self explanitory. Set this to the number of threads your cpu has.
+Self-explanatory. Set this to the number of threads your CPU has.
 
 
 ##### `--end-usage=vbr`
@@ -254,14 +253,14 @@ Set the average quantizer level.
 
 This last portion tells which files to use for the input and output.
 We use `-o` to tell which filename to write the encoded file to.
-In the first case, vpxenc will write a file at `/dev/null` which is
-the null device on posix systems (meaning no file will be written
-for the first pass (if you're on windows simply use the filename nul
-instead)). In the second pass we write an ivf to `myvideo.ivf` in the
+In the first case, vpxenc will write a file at `/dev/null`,
+the null device on POSIX systems (meaning no file will be written
+for the first pass (if you're on windows, use the filename nul
+instead)). In the second pass, we write an ivf to `myvideo.ivf` in the
 current working directory.
 
 The last argument we are passing to vpxenc is the input file.
-As we are doing a two pass encode it is more efficient to save the
+As we are doing a two-pass encode, it is more efficient to save the
 output of vapoursynth then run the encode on that instead of running
 vapoursynth twice.
 
@@ -275,7 +274,7 @@ TODO
 We covered the basics of how to encode using the vpX/aom family of
 codecs, including speed presets.
 
-Here is a summary of when to use vp9 vs AV1 (please note these are
+Here is a summary of when to use vp9 vs. AV1 (please note these are
 recommendations, you do not have to follow them):
 
 - Is your source larger than Full HD?